Mercuriceratops: With bony wings on its skull, dinosaur looked fly

Mercuriceratops

Danielle Dufault

Mercuriceratops gemini (center) had strange wing-like protrusions on its frill, unlike the horned dinosaurs Centrosaurus (left) and Chasmosaurus (right), also from the Dinosaur Park Formation in Alberta, Canada.

Mercuriceratops gemini (center) had strange wing-like protrusions on its frill, unlike the horned dinosaurs Centrosaurus (left) and Chasmosaurus (right), also from the Dinosaur Park Formation in Alberta, Canada. (Danielle Dufault)

A team of paleontologists has discovered a horned dinosaur with some seriously weird headgear. Meet Mercuriceratops, a Triceratops relative whose bony frill sports wing-like protrusions on either side of its head.

The discovery, described in the journal Naturwissenschaften, highlights the diversity of the frilled dinosaurs, which could help shed light on their evolutionary history.

Weighing in about 2 tons, Mercuriceratops gemini might dwarf your average ox but was still smaller than its well-known cousin Triceratops, which was probably nearly twice its size. Mercuriceratops -- named after Mercury, the Roman messenger god who sported wings on either side of his helmet -- was probably a plant-eating dinosaur with a beak-like mouth that lived 77 million years ago during the late Cretaceous period.

“We would never have predicted this from our experience with working on horned dinosaurs,” said lead author Michael Ryan, curator of vertebrate paleontology at the Cleveland Museum of Natural History. “It’s modifying an element of the skull that’s never been modified before.”

The researchers based the discovery on two separate fossil fragments – one found in north-central Montana and the other discovered in Dinosaur Provincial Park in Canada's Alberta province.

When a single fossil is discovered, it’s often difficult to tell whether it’s a new species or just a standard variation, or weird mutation, of a known animal. But the fact that these two fossils with the same butterfly-like protrusions were found hundreds of miles apart showed that they must be members of an undiscovered species. (The two fossils, from the right side of the frill, are what earned Mercuriceratops the name “gemini,” Latin for “twin.”)

These ceratopsians – Greek for “horned faces” – were a diverse group, Ryan said, and understanding their diversity can help researchers better track their evolution and species differentiation. The researchers think the wing-like protrusions were ornamentation to attract mates, and it’s possible that female preferences may have been driving natural selection in male headgear.

Mercuriceratops

Naturwissenschaften

These two skull fragments from Mercuriceratops were discovered hundreds of kilometers apart, and both come from the right side of the bony frill around the animal's head.

These two skull fragments from Mercuriceratops were discovered hundreds of kilometers apart, and both come from the right side of the bony frill around the animal's head. (Naturwissenschaften)

Ryan compared the effect to the tail fins adorning flashy cars from the 1950s.

“This animal is trying to trick itself out to attract mates, and it’s doing so in a very unusual way,” Ryan said.

The phenomenon is similar to male peacocks, who flash their jewel-toned plumage to impress the relatively dowdy peahens -- or in bighorn sheep, among which the males with the largest horns often win the mates. It's an age-old evolutionary arms race -- or a horns race or a feathers race or a frills race, depending on the species.

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